Electric plug



P 1940- E. F. TOWNSEND 2,195,546

ELECTRIG rw Filed Jan. '14, 1959 2 Sheets-Sheet 1 jaw/m0 I." YE /-155Mb,

I Aitomgys Patented A e- .2, 1940 4 UNITED STATES PATENT OFFICE gELECTRIC PLUG i Edward F. Townsend, San Antonio, Tex. I ApplicationJanuary 14, 1939, serial No.'251,012

. 1 Claim. (o1. 173-361) The present invention relates to electricattachment plugs and has for its primary object to provide a yieldablemounting for the prongs of the plug whereby the prongs are heldin adiverging projecting position, the prongs being mounted for slidablelateral movement against the tension of a. coiled spring engaging theinner ends of the prongs whereby the outer ends of the prongs, wheninserted in a receptacle, will have '10 a binding engagement with thewalls of the receptacle as well as with the contacts thereof.

- A further object is to provide an attachment plug of this character ofsimple and practical construction, which is strong and durable, effl-'15 cient and reliable in performance, relatively inexpensive tomanufacture and otherwise, 'well adapted for the purposes for which thesame is intended.

Other objects and advantages reside in the I details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, andin which- Figure 1 is a topplan view.

Figure 2 is a similar view showing the'plug engaged with a receptacle,the'latter being shown in section.

Figures 3 and 4 are end elevational views show- I so ing the oppositeends of the plug.

Figure 51s a plan view with one of the sections of the shell of the plugremoved.

Figure 6 isa longitudinalsectional view taken substantially on a line 66of Figure 5.

Figure 7 is a transverse sectional view taken substantially on a line'II of Figure 5. i Referring now to the drawings in detail, the numeral5 designates the shell of the plug which is formed of a pair ofinsulationsections ofsubstantially flat formation and detachablyconnected to each other by means of a pair of bolts 6.

An opening I is formed in the rear'end of the,

shell for receiving the usual circuit. wires and apair of openings 8 areformed in the front end of the shell through which the prongs B-proiect.

The prongs 9 are maintained in spaced diverging relation by alongitudinally extending rib l0 formed in the abutting face of eachsection of the shell and having oppositely inclined side faces I Iagainst which the prongs normally lie, as clearly illustrated in Figure5 of the drawings.

.Each of the prongs is yieldably held against the rib III by a coiledspring l2 extending laterally of the shell and having one end seated'ina recess l3 formed therein. The inner end of each of the prongs isformed with a lateral extension M within which a terminal screw 15 isthreaded for at- 5 tachirig the circuit wires-thereto.

Each ofthe prongs are provided with an opening IGthrough which a pin I1is inserted to provide for the free sliding movement of the prong on thepin, the ends of the pins being seated in 10' recesses N in the oppositewalls of the openings 8, the pins being positioned outwardly withrespect to the springs I2 as clearly illustrated in Figure 5 of thedrawings.

From the foregoing construction it will be apll parent that when theprongs '8 of the plug are inserted in the recesses IQ of a threadedreceptacle 20 that the plugs will bind against the edges of the recessesat the point indicated at 2| causing the spreading of the prongs againstthe ten- 20 sion of the springs l2 while the extremities of the prongswill bind against the contacts 22 of the receptacle. The prongstherefore will be maintained in tight contact with the contacts 22 ofthe receptacle and will also be held in binding 26 engagement withrespect to the edges of the recesses of the receptacle to preventaccidental withdrawal of the plug.

It is believed the details or construction of the device will be readilyunderstood from the foreso going without further detailed explanation.,Having thus described the invention, what I claim is- An electricconnecter plug comprising a shell composed of a pair of duplicate'shellsections, 35 each section including a central rib having outwardlydiverging side walls and forming a partition in the section ,to define apair of passages communicating with the interior. of the shell andhaving outer ends opening through one end of w the shell, recesses inthe opposed walls of the passages adjacent their outer ends, pinsbridging the passages and having their ends loosely seated in saidrecesses, a conductor prong freely positioned in each passage andslidablymounted on w each pin with one end projecting outwardly of theshell, recesses in the walls of each section inwardly of the pins and, acoil spring seated in each of said recesses and bearing against theprongs to yieldably urge the prongs against opposite wsides of the ribs.

' EDWARD B. TOWNSEND.

